Automatic locking retractor

Abstract

Disclosed herein is an automatic locking retractor suitable for use in a vehicle seat belt. The retractor does not produce any substantial unpleasant noise when the webbing is wound up, because its cog wheels and lock lever are kept separated while the webbing is wound up. The retractor features use of a ratchet wheel, latch gear and control member. The ratchet wheel and latch gear are rotatable together with the cog wheels. The control member is normally kept in engagement with the latch gear but can assume a first and second working positions when the webbing is pulled out and taken up respectively. At the working positions, the control member is kept in contact with the path of rotation of the circumference of the latch gear. When the webbing is pulled out, the pawl engages with the control member but is kept out of engagement with the ratchet wheel. When the webbing is then wound back over a small length, the pawl is disengaged from the control member but is then kept engageable with the ratchet wheel. When the webbing is pulled out again, the pawl is brought into engagement with the ratchet wheel and the lock lever is brought into engagement with the cog wheels to restrain any further release of the webbing.

What is claimed is: 
     
       1. An automatic locking retractor comprising: a casing;   a take-up spindle rotatably supported on the casing and urged in the winding direction of a webbing;   a cog wheel mounted integrally on the take-up spindle;   a ratchet wheel and latch gear integrally rotatable together with the cog wheel;   a lock lever displaceable between a first position where the lock lever is in engagement with the cog wheel and a second position where the lock lever permits free rotation of the cog wheel;   a pawl displaceable between an engagement position where the pawl is in engagement with the ratchet wheel, an intermediate position where the pawl is engageable with the ratchet wheel and a non-engagement position where the pawl is kept out of engagement with the ratchet wheel;   a control member normally biased to a position, where the control member is engageable with the latch gear, and capable of assuming a first working position where the control member is brought into contact with the path of rotation of the circumference of the latch gear by a rotation of the take-up spindle in the pulling-out direction of the webbing and a second working position where the control member is brought into contact with the path of rotation of the circumference of the latch gear by a rotation of the take-up spindle in the winding direction of the webbing; and   sensor means coupled with the pawl and adapted to hold the pawl in the non-engagement position when the webbing has been wound up over at least a predetermined length;   wherein the control member moves toward the first working position and is brought into engagement with the pawl and the pawl assumes the non-engagement position when the webbing which has been wound up on the take-up spindle is pulled out, the control member moves toward the second working position and is disengaged from the pawl and the pawl moves to the intermediate position when the webbing has been wound back over a predetermined small length, and the pawl is then guided to the engagement position when the webbing is pulled out again; and means for displacing the lock lever from the second position to the first position as the pawl is displaced from the intermediate position to the engagement position.   
     
     
       2. The automatic locking retractor as claimed in claim 1, including means for pivotally supporting the control member on the casing. 
     
     
       3. The automatic locking retractor as claimed in claim 1, including means mounting the lock lever and pawl for movement relative to each other. 
     
     
       4. The automatic locking retractor as claimed in claim 3, including means for urging the lock lever toward the second position and means for urging the pawl toward the engagement position. 
     
     
       5. The automatic locking retractor as claimed in claim 4, wherein the means for displacing comprises means on said pawl for engaging the lock lever when the pawl has moved over at least a predetermined distance. 
     
     
       6. The automatic locking retractor as claimed in claim 1, wherein the control member has a first arm engageable with the latch gear and wherein the means for displacing comprises a second arm on the control member engageable with the pawl.